"Paul Scott" wrote:

"lonelytraveller" wrote in
message
...

So either they've built a huge expensive glossy wall, just before they
need to demolish part of it, or the wall somehow has the ability to
easily vanish, without drilling.

So what's going on with the wall?

Found this picture of the works at Blackfriars, since posting the earlier
reply, which may be relevant to this. Shows how a fairly solid looking
stone wall can be fabricated. No guarantees that the wall at Farringdon is
exactly the same but it seems quite possible:

http://www.flickr.com/photos/ianvisi...n/photostream/


The picture is a very good illustration of a technique known as
"curtain walling" which is used very extensively in modern office
buildings. A light and very efficient steel or aluminium structure
carries glass or thin stone panels or a combination of the two. There
is some adjustment available in the metal structure to cater for the
tolerances of the (usually) reinforced concrete structure and give a
near-perfect finished building.

It has also been used to re-clad some older buildings, changing their
appearance and adding modern standards of weather protection. Some
pretty awful 1960s offices and blocks of flats have been brought up to
date in this way.

The stone panels are mostly produced in Italy and Norway. Large stone
blocks are very carefully quarried so they come out square. Then the
blocks - usually either granite or marble - are precision sawn using
large diameter diamond-tipped circular saws. The thickness is
typically a couple of centimetres, but the finished job often looks as
though it is made of solid granite or marble that is tens of
centimetres thick.